


Brothers Black

by IceJazzElleth



Category: Harry Potter - J. K. Rowling
Genre: Alternate Universe - Canon Divergence, Blood Magic, Brothers, Family Feels, Family Reunions, Gen, Hurt/Comfort, Regulus Black Deserves Better, Regulus Black Lives, Regulus turns spy
Language: English
Status: In-Progress
Published: 2020-11-07
Updated: 2020-12-12
Packaged: 2021-03-09 01:22:30
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 7
Words: 13,597
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27436528
Author URL: https://archiveofourown.org/users/IceJazzElleth/pseuds/IceJazzElleth
Summary: “You see,” Regulus began, sniffing with an air of superiority. “There have been plenty of wars in Wizarding history that have divided and split families. Loyalties. Therefore, if blood was asked to kill blood, a way was found. Because as much as you may despise us, despite mother blasting you from the tapestry and cursing your name, we are still brothers. The blood that runs through your veins is as Black as mine.”Upon realising that his demise during the retrieval of the Locket would serve little purpose, Regulus Black decides to find a more sure proof way to defeat the Dark Lord and so becomes a spy in order to gather further knowledge. In doing so, he ends up running into his brother, captured by Death Eaters. Knowing that he will likely be ordered to kill Sirius, Regulus finds a way to keep face with Voldemort while also saving his brother. With Sirius now an impromptu permanent guest (see prisoner) in Regulus' hideout, can the two brothers put aside their differences and join forces to take down Voldemort?
Relationships: Regulus Black & Sirius Black
Comments: 46
Kudos: 116





	1. Prologue

Blood Magic.

It was powerful. It was dark.

It’s very existence once had assured Regulus of his steadfast beliefs on pureblood supremacy. Magical blood was full of potential. Potency. Did it not make sense that purebloods would have more of it running through their noble veins?

Of course, it was a subject not oft studied. But the Black family library had been well stocked. Regulus had become very well versed before he had declared his allegiance to the Dark Lord. And when it had shifted, he had yet thrown himself in with more vigour (because even if the Dark Lord was wrong, surely blood supremacy was not). Clinging onto whatever semblance of his childhood rearing that he could.

In a strange twist of fates, Regulus smirked beneath the mask, it would be his brother’s saviour. This dark magic that his oh so pure and noble brother sought to deny.

The screams rang out. Had he been someone else, Regulus supposed he might be grateful to wear the mask which hid any emotion that might flicker across his face and betray his new loyalties. But he was Regulus Arcturus Black, descendant from a long line of noble and most ancients Blacks. His cunning and ambition would not allow something so minor as facial expression to ruin his plan.

Bellatrix laughed, as she so often did and Regulus’ dark eyes shifted to the Dark Lord. He had it on good authority that he would be asked to put his brother out of his misery. That was important for the magic. Regulus had taken minor action to shift the likelihood that this request would be made of him ever since he had learnt of his brother’s capture. Furthermore, he had a plan for if he was not asked. He could deal with the anger aimed at him for an unwarranted killing curse. But seeing as there had been doubts about his loyalties since Kreacher’s return from the cave... He was a good liar, but they could feel the change, if subconsciously. Like the drop in pressure before the storm.

“Lestrange, cease. I believe we have got all we can out of this one.” The Dark Lord ordered.

She looked towards him, a pout on her face. She rarely wore the mask.

“Aw. Shame. I enjoy getting my cousin to squirm.” She said, casting a longing glance back at Sirius’ trembling form. A true Gryffindor, Regulus reflected. Sirius had given up no secrets.

“Black.” Voldemort ordered. Regulus straightened and stepped forward.

“My Lord.”

-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-

Sirius panted as he lay on the dirty floor. Panted like Padfoot. Small thoughts like that to keep him going. Internal humour. Pretend jokes with James. Anything to keep him from focusing on the pain the Death Eaters inflicted. A safe place in his head where the Marauders laughed and joked as if nothing was going on. He was dully aware that his leg may be broken. His fingers crushed. Body bleeding out. But the glory of crucio was that none of that really mattered in comparison

Black… when did they call him that? Normally it was Blood Traitor. Scum. Filth. All of mother’s pet names for him…

Ah.

His eyes focused on the figure who stepped forward. Perhaps Voldemort not talking to him. He recognised that voice which answered the call. Perfectly controlled and measured. Well, what a family reunion.

Sirius’ face twisted into a sick grimace.

“So this is what you’ve done with your life, Reggie.” He spat, giving a cough. The masked man looked at him with impassive dark eyes as if he were dirt rather than Regulus’ brother. Well, they hadn’t been on speaking terms since he left. Sirius shifted but his body cried out. The pain from crucio lessening and letting his body could speak out about the physical pain.

Was it weird to miss crucio?

“You have been a loyal follower, Black. I am sure you will delight in this chance to prove yourself to all of us gathered here and rid your family line of this blood traitor.”

It was sick, really, Sirius thought as he stared up at his brother. That Voldemort would ask his brother to kill him. To die by his brother’s hand… it added pain and injury to his already pain soaked body. He stared down at the wand, refusing to let the hurt show in his face.

“Yes, be a good little Death Eater, Reggie. Do as your Master commands.” He smirked, declining to go down with anything less than a tease on his lips. He was Sirius Orion Black and he didn’t do things by halves.

Why did speaking hurt so bad?

“Wait!” Voldemort said.

Sirius noted Bellatrix had whispered into his ear. Perhaps he would be tortured by his _brother dear_ first before finally being put out of his misery. Well, they weren’t bad guys for nothing.

“Well, don’t keep me waiting.” He coughed.

“Remove your mask, Black. Let us all see your loyalty.”

Sirius closed his eyes.

It was one thing to know your brother was your executioner. Another to have to look him in the eyes. He waited for the curse.

Well, he had had a good run of it. Even been asked to be the godfather to Prongs’ wee one when he was born. It had been an honour. He only wished he had the chance to see the little tyk-

“Avarda Kadarva.” Regulus whispered.


	2. Reunion

**Summary for the Chapter:**

> Sirius awakes from his apparent murder in a strange location and finds a familiar (if somewhat unwelcome) face.

The first thing that Sirius realised was that his body did not hurt nearly as much as it should. He’d taken a decent amount of torture and it wasn’t like the Death Eaters were going to offer him any healing. That would have been counteractive to their aims and general objectives of evilness.

The second thing he noted was that he should be dead.

The last thing he remembered was his brother uttering the killing curse and a flash of pure green light.

He didn’t feel dead. He felt like he was in entirely too much pain for the afterlife. And not enough pain for actual life. Sirius waited, to see if any answers would come out of the black void of his mind as he remained lying down. On something soft. So… not a prison cell. Slowly, he cracked his eyes open to see what surrounded him.

The room was huge and lofty. The walls were russet brick work, industrial. Like the old muggle factories that Lily had pointed out on their various walks around muggle London that Sirius had demanded. He had wanted to know all he could about the muggle world. Their history fascinated him. Something he had never had a chance to learn about. Their technology, however, had first place in his heart and Sirius noted with some delight that there was a huge television mounted on the wall. It was with a small frown, that his eyes were drawn to its power cord which hung limply, as if forgotten. He opened his eyes a tad wider. The room had been dressed up grandly. Giant wooden table with a candelabra decorating it, candles flickering merrily. Grand fireplace. Marble coffee table.

The room had electric lights but they weren’t on. Candles lit the entire place. Just like they would in a wizarding home.

The sofa beneath him was black jacquard, the blanket he’d been deposited on was a fine silver velvet. An armchair sat not too far. Black jacquard again… And…

Sirius stumbled to his feet. His broken leg, though on the magical road to recovery, cried out in protest. The world swayed dangerously around him. He reached for his wand but it had been taken when the Death Eaters had first captured him.

Sitting in the armchair, calmly reading a book (on astrophysics of all things) was his killer.

“Sirius.” Regulus acknowledged, glancing up and carefully sliding a bookmark into the pages.

Regulus was dressed in a smart black suit, with a deep purple shirt and silver cuff links. He looked entirely unlike himself, Sirius thought. Muggle clothing? Since when would Regulus be caught dead in such things?

Regulus had been with the Death Eaters. Regulus had killed him!

Sirius was smart. Top of his class half the time – and with competition such as James, Remus and Lily, that had been impressive – but even with his vast (because Sirius was _so_ humble) intellect, he could not string any of the pieces together.

“Y… You killed me!” He managed to get out. Not his wittiest. Sirius winced. He’d work on fixing his reputation as the ultimate wisecracker.

Regulus sighed, calmly placing the book on the grand coffee table.

“Regrettably.” He commented, rising. Sirius stumbled away. The memory was fresh. Regulus frowned and raised his hands.

“You can pat me down, I’m not armed. On the table in front of you are some healing potions.”

Sirius glanced back at the coffee table that stood between them. His eyes were coming into sharper focus as his mind and body began to wake from his sleep (his death?). Little glittering vials had been carefully arranged before him, their colourful contents clear through the intricately decorated glass. Regulus had always been pretentious.

“There’s a room prepared for you down the hall. And a bathroom. You can clean up in there. I’ve got spare clothes. I had to guess the fitting. Dinner is at 7:35 sharp. Do not be late.”

“What. The. Fuck?” Sirius asked, staring at Regulus.

His brother only proceeded to look at him with an irritatingly blank expression.

“You killed me, Reg! I saw the curse!”

He arched a delicately carved eyebrow.

“I found a… way to negate that little problem.”

“Little problem? Oh, so killing your big brother for your new master is a little problem. What did you do to me, Regulus? Am I some sort of inferius? A Zombie? Vampire? Reanimated corpse? Frankenstein’s Monster? Oh, you don’t know what that is… it’s a muggle thing. Dead guy put together and brought back to life. I guess that’s the same as a reanimated corpse. I don’t feel like a reanimated corpse. Merlin! Regulus. Are you going to answer me?”

Regulus waited, making sure that Sirius had ceased his stream of questions and was ready to listen. He did wish that his brother had opted for a shower and dinner before beginning this line of questioning. Sirius had always been impatient.

“You see,” Regulus began, sniffing with an air of superiority. “There have been plenty of wars in Wizarding history that have divided and split families. Loyalties. Therefore, if blood was asked to kill blood, a way was found. Because as much as you may despise us, despite mother blasting you from the tapestry and cursing your name, we are still brothers. The blood that runs through your veins is as Black as mine.” He paused here for a small and dark chuckle of amusement.

“So, my dear brother, I formed a blood connection between us. As I was to be the killer – and I was certain the Dark Lord would want me to prove my undying loyalty-” His face twisted into an unpleasant smirk at this. “- It was I who had to perform the necessary rituals and sacrifices. When I fired the curse, we were linked and shared it. The killing curse can kill only one, so therefore, we both survive.

“Of course, I felt it and I had to hide what I had done from the Dark Lord and that I performed admirably. You only had to enter a stage between living and death, so not as to arouse suspicion. Once they were assured of your demise, I requested permission to bury you in an unmarked grave near the Black family Crypt, as only befitted a traitor, but one of our blood. This, I was granted and so I smuggled your body out, performed what healing magic I could and brought you here. My sanctuary from the War, where none would seek to find me.”

Sirius was staring at him, grey eyes wide in horror.

“Blood magic?” He said. Regulus sighed. Sirius was so awfully wrapped up with his own ideas of purity. Purity of magic. The notion that there was a light side that had no taint upon it.

“Blood magic.” Regulus confirmed, noticing the disgust in his brother’s face.

“We’re not the same blood. I left that place. I’m not one of you.”

“You can try to deny it, but you would be dead if it were not the case.”

“I’m not sure if I want to be alive if it’s because of blood magic. Because I share your blood.” Sirius hissed. Regulus merely slowly blinked at him.

“Are you so dedicated to your hatred and self-denial of family that you do not even question why I, a Death Eater, would go to lengths to preserve your life?” He asked. Blood magic was risky. If he had not performed the rituals and sacrifice correctly, they could have both lost their lives or worse. It was not magic to be undertaken lightly or on a whim.

Sirius paused.

Regulus watched as his brother glanced around the room. Regulus’ carefully crafted penthouse lair in the muggle world. Where none of his former allies would seek to find him. A place where he denied himself magic for fear that it would alert the Dark Lord. A place, which was for all intents and purposes, Muggle.

“You’re shit at pretending to be a muggle.” Sirius said, breaking the silence.

Regulus frowned. He had gathered items that he had seen in the houses of Mudbloods and Blood Traitors. He had obliviated many muggles in his attempt to create this perfect haven.

Sirius broke out into laughter and Regulus’ frown deepened. The Cruciatus curse could cause madness it was hypothesised, given long enough exposure. And the Black family already had a penchant for it. That, Regulus knew well. He stepped forward, concern warring on his face.

“Fuck. You have no idea. Really.” Sirius was doubled over in laughter. “You look like some kind of vampire and you have a gothic house and you haven’t even plugged in that giant ass television. Do you even know how to work… Never mind.”

Sirius plonked himself back onto the sofa and started to sort through potions. He gulped down several, content that they were not poison.

“Yeah, that’s the stuff.” He muttered, closing his eyes.

Regulus really wished his brother would wash. Sirius was disgusting after days of torture. The blanket would have to be thrown.

“So… you’ve turned double agent, huh? I would say triple but I don’t think Voldemort would approve of this, even if it were to trick me into giving up some Order secrets.” Sirius commented, downing another pain potion, and gesturing to all the muggle accoutrements.

“More that I have my own personal reasons.” Regulus said, easing his way back to the armchair, dark gaze never leaving his brother.

Sirius let out a bark of laughter.

“What did he do? Don’t tell me it was because I got captured and you only just got some familial feelings and realised that I’ve got a huge fucking target on my back.”

All things considered, Regulus thought Sirius was taking this very well.

“Kreacher.”

“That mad House Elf?”

Regulus gave a nod and Sirius let out a breath.

“Well, I always knew you were stupid. So what, you decided to join old Voldey-wart and went along with murder and torture but then Kreacher changed your mind?”

“The Dark Lord hurt Kreacher-”

“The Dark Lord? Merlin, Regulus! If your going to be a full-blown traitor you need to stop sounding like one of his fanatics. And what? You go around killing and torturing but draw the line at anyone harming that foul beast of a House Elf. What kind of morals is that?”

“Mine.” Regulus said, his voice low and dangerous. Sirius paused, pushing his hair back out of his face.

The two brothers stared at each other, gauging the situation. It had been three years since they had last spoken. Sirius looked at his brother. Somehow, Regulus was paler than normal, his eyes sunken that little bit more into deep eye sockets. The dark eyes had increased in intensity and were like pools of still dark water in an endless cavern. He couldn’t help but notice how the tips of Regulus’ fingers twitched oh so slightly. A restless, nervous energy that had been trained out of them by their charming mother. She had never approved of fidgeting.

“You said there’s a shower down the hall.” Sirius said at last, breaking the silence. He saw his brother ease up.

“And a room made up for you. I’ll show you.”

Sirius waited for his brother to rise, noting the small, subtle sharp movements and the way his eyes would occasionally dart; a wired energy which was not too dissimilar to Sirius when he overdosed on coffee – too regular an occurrence.

Fuck. He knew his brother. He didn’t want to. He did not want to acknowledge that the same blood ran through their veins. But he knew Regulus and his mannerisms. Something had caused Regulus to betray the Death Eaters but still hide in their midst. Something had shaken his pureblood little brother into betraying every one of the family’s stupid ideals that had been etched into their very being.

And all that Sirius could think was if it was so bad that Regulus would betray his heritage, it did not bode well for the Order. Not one little bit.

**Notes for the Chapter:**

> Seeing as the prologue was brief (and a prologue), here's the next chapter of this story. I'm hoping to try and update on a weekly basis, although sometimes I might be more frequent or less frequent depending on work load and where these two brothers decide to take the story. I hope you enjoyed this update!


	3. Decadence

**Summary for the Chapter:**

> Sirius investigations his new bedroom and tries to figure out Regulus.

Sirius stared at the room that Regulus had prepared for him. The walls were that same industrial brick, bare apart from the occasional muggle artwork that failed to give the place a more lived in touch. A fireplace had been cut into the wall and grandly fronted with marble. In the centre was a four-poster bed with black sheets and an ebony wooden frame. Trust his brother’s little dark heart to make this place seem as Black as he could.

But the curtains around the bed and over the window were a deep burgundy and the fabric was expensive and well cut. There was a runner along the bed of the same red, clearly chosen (or made) to match. The nightlight by the bedside had a dark claret lampshade. When he turned on the lights, Sirius could pick out hints of gold in the curtains that glistened and glittered in delicate, winding patterns. Everything had been carefully chosen to match and to reflect his Gryffindor status while adhering to the Black standard of grandeur and general creepiness.

There was no way that Regulus could have prepared this during Sirius’ time as a prisoner of Voldemort. This had required forethought. More than was due between such estranged brothers.

Sirius’ hand brushed against the heavy curtain fabric, feeling its richness and distinct lack of magical air that he would have expected of cloth woven for a pureblood wizarding family. To acquire all this from the muggle world would have taken even more time. As Regulus was still with the Death Eaters, he would have had to carefully transfer money without them noticing. Find time to set this up. Which meant that his brother’s defection must have happened a while ago. That at some point, Regulus had set this up, hoping that he, Sirius, would move in.

It had been three years since he had last spoken to his brother. Three years and not a single word between them. No Christmas cards, no birthday cards. Why hadn’t Regulus come to him? If he had bothered to go to these lengths to try and make this room something he thought Sirius would accept, surely he could have written him an owl? With a note of concern, Sirius wondered if he was that unapproachable. He had always thought he’d been open and friendly to his brother. Someone that Regulus might turn to if he grew the guts to step away from what mother and father wanted of him.

Sirius sighed and out of reflex, carefully folded his towel and hung it over the back of a chair. Normally he would have just let it fall to the floor and worry about its damp mess later. But Mother had been ferocious, and this house uncomfortably reminded him of his childhood.

The wardrobe was carved in dark wood, not ebony, but varnished to give a close approximation. There were suits. Sirius rolled his eyes and pushed on. Finally, he found some dark blue jeans that suited him (Regulus must have realised that having the option of jeans would be welcome) and paired it with a black shirt that was too formal for his liking but would do. Sirius cast a customary glance at his reflection, sweeping long, black hair back over his shoulders. He looked remarkably good for someone who had been killed only a couple of hours ago.

The clock read 7:26 and Sirius decided he had spent enough time keeping his brother waiting.

Regulus was always very punctual and expected others to be so. Early was preferential.

Striding into the Living Room, Sirius was greeted by silence. The dining table had been set with silver cutlery and a glass of red wine for each of them. It glistened almost sinisterly in the candlelight and Sirius really had to marvel at how Regulus thought that this might look like a muggle home.

A door further on had a light and from it came the sound and smells of cooking.

Curiosity drove him forwards and Sirius was greeted by the oddest sight he had seen in his life. And he spent his full moons with a werewolf, deer and rat.

Regulus was standing at a stove, watching a cast iron skillet come to heat. A creamy sauce simmered gently behind the skillet and an oven had been on. Sirius sniffed the air.

“Rosemary… garlic... truffle.” He commented from his place, slouched in the doorway. Regulus glanced over to him.

“Roasted potatoes, cooked in olive oil, rosemary and garlic. A cream and truffle sauce to go with our steaks. You still take yours black?” He asked, wrinkling his nose.

“Medium now, actually.” Sirius commented. The wrinkle of disapproval remained but lessened. Regulus placed a steak in the pan and watched it with an intense focus. Sirius waited for an explanation. Regulus turned the steak over. The silence increased.

“Merlin, Reg, this is weird. Are you going to just confound me into spilling all my secrets? Is that your great master plan?”

Finally, Regulus looked away from his cooking, meeting Sirius’ eyes.

“I’m not trying to get you to tell me anything. You need to eat. I doubt the Dark Lord let any nutrition touch your lips while you were in his clutches.” Sirius was not proud that his stomach did a squelch, as if to punctuate the truth of those words.

“I mean cooking. What was it Mother told us? ‘A Black never sullies themselves with menial duties. That’s why we have House Elves, to handle those disgraceful tasks.’.” Sirius said, in a perfect imitation of their mother, if he did say so himself. Regulus snorted in amusement but forced his face back into a neutral position.

“This is a hideout, so the Dark Lord won’t discover my treachery. I cannot risk too much magic here, even House Elf magic. I have got wards, of course. Carefully constructed to conceal their presence and mine. And I’ve warded what feels like at least ten percent of Muggle London as decoys to try and keep anyone off my tracks. But that means I must do the cooking while here. It is not too bad; I find it a lot like potions.”

The steak was carefully placed on a plate and Regulus put a second one on.

“I never thought I’d see the day. Are you going soft, Reggie?” Sirius teased. His brother frowned but did not deem to give him a response. The second steak was cooked much faster and placed on another plate. The oven was opened and a sparse amount of roast potatoes were neatly deposited next to the meat. Then the truffle sauce poured over the steaks with delicate shavings of truffle carefully arranged on top as a garnish.

Sirius followed as Regulus brought the food through and placed the plates down on the table. He returned to the kitchen and brought out a salad and dressing in a silver dish.

“If I had known getting tortured would make you wait on me hand and foot, I would have done it sooner.” Sirius commented, watching this all before taking a seat, letting it scrape against the ground. Regulus winced.

“How can you joke about that?” Regulus asked softly, taking his place at the other side of the table and meeting Sirius’ eyes.

“Easy.” Sirius shrugged, cutting into the steak while his brother helped himself to salad.

Merlin! Regulus was an amazing cook. The flavours were balanced to perfection, the steak cooked just to the right level. The potato was crunchy on the outside and fluffy on the inside. Sirius couldn’t remember the last time he had such good fair. Probably James and Lily’s wedding. And Hogwarts before that.

“You’re good!” He exclaimed around a mouthful, still ignoring the strangeness of the situation.

“You should have some salad.” Regulus said pointedly, sliding the bowl over to him. Sirius rolled his eyes but helped himself.

They munched in silence, sipping on the red wine. That was a good vintage – Sirius definitely hadn’t had a red wine that good since he had left Grimmauld Place. He had known that the muggles made great drinks. After all, he loved their cocktails, a delicious splendour that had yet to make its way to the wizarding world. Yet he had always found their wines, brandies and whiskies to be lacking. Perhaps he should have been spending more on booze if this was what it brought. He had no doubt Regulus would have spent a lot and considered it pittance.

Perhaps that was what this was, Sirius mused, lowering his glass. Bribery. Regulus shows up and offers him the comforts that the wealth of the noble and ancient house of Black could buy. But to what end? Certainly not for Voldemort and the Death Eaters. He had ruled them out. Mother? She’d likewise have a heart attack seeing Regulus in this place. Which meant it still had to be the first option. That Regulus had been a Death Eater and had betrayed them.

And for some idiotic reason, hadn’t come to him or the Order for protection and decided to strike out alone.

Sirius pressed his lips together, not for the first time wishing he could figure out what on heaven and earth went on in Reg’s mind. His brother had always been a mystery. Willing to sprout pureblood prejudice and hatred and on the next breath berate him for speaking harshly to Kreacher (despite the House Elf damn well deserving it).

“Do you want me to turn the telly on?” Sirius asked. He hated the silence. Always had. Silence was a suffocating presence and it was only made worse by the wait for Regulus to explain anything.

“Telly?” Regulus asked with a frown.

“You know, that giant thing you’ve got on your wall. Probably very costly.”

“Oh, the thing that they said there are packages for, but none arrived.”

“Packages… How many channels did you get?”

“The most I could. A Black would never settle for something substandard.”

“And you haven’t even used it!”

“I don’t know what it does!”

“Then why did you buy it?”

“…”

Sirius watched as Regulus couldn’t meet his eyes, focusing on slicing his steak, getting a correct amount of sauce on it. Onto his fork. Chewing oh so slowly. The movement of his throat as he swallowed. Finally, Regulus answered, still not meting his eyes.

“All the muggle and mudblood houses I have seen had them. I figured it was a vital part of the charade.”

Sirius stared, mulling over the words. He wasn’t an auror and a member of the Order of the Phoenix for nothing. The only reason Regulus would be going into those houses were if he had been sent to attack them. And Sirius knew all too well what Death Eaters did when they attacked houses. He had seen the aftermath. He had seen the bodies. He had comforted those who had been left to slowly perish in the remains of what had once been their homes. He knew why his brother would not meet his eyes.

Somehow, it had been easy to pretend that Regulus hadn’t killed when the only one he knew his brother had fired the killing curse at was himself. He had distanced Regulus from the myriad of horrors that Sirius had witnessed caused by those that Reg worked with. Imagined that apart from that one killing curse fired at him (and what were Unforgivables amongst family?), his brother might have kept himself clean.

Knowing that Regulus had gone out and killed other innocents - potentially tortured, a traitorous mind whispered - and had the audacity to examine their homes and gather intel for his own treachery did not sit well with Sirius. He looked down at the meal. It had tasted so good.

“I think you need to start at the beginning, Reg. And leave nothing out.”

**Notes for the Chapter:**

> It's always awkward when you end up kidnapped by estranged brothers who have joined death cults, isn't it? Next chapter should have an explanation on how this is became an alternate universe and more Regulus screen time.


	4. Murderer

**Summary for the Chapter:**

> Regulus discusses the events leading to him joining the Death Eaters and then defecting.

“I became a Death Eater when I was sixteen years old. After you left, Mother’s expectations that I would join the Dark Lord’s cause increased in vigour. She wanted a son to make her proud – no offence – and I was only too eager to please. Many of my ideals, as well you know, do naturally align with the Dark Lord’s agenda. After all, blood holds power. Not that you agree with me on this, and I will respect that, I do not desire to get into an argument. I received my mark-” At this, Regulus slipped an arm out of his jacket and raised a sleeve to reveal the Dark Mark on his pale skin. Sirius stared.

“Reg…” He breathed. “How…”

“How could I let my skin be flawed by the mark of the Dark Lord?” Regulus asked, raising an eyebrow, tugging down his sleeve and adjusting his jacket. “I was firmly entrenched in his ideology. While you may have seen school as a safe haven, it was far from it. Dumbledore’s policy of Gryffindor favouritism drove many Slytherins into the open arms of the Dark Lord, who promised that we would be loved and accepted; when all else hated and despised us. He painted visions of a world where the pure blood families would be great once more and wield the powers that our forebears once had. Simple rhetoric, I know, and I am ashamed to have been taken in. But we were all young, still at school and could not have known much better. I was surrounded by those who would become Death Eaters, or already had, from an early age, my choices were limited. It was not long after by seventeenth birthday, when the trace was removed, that I… went on my first raid.”

Sirius looked at Regulus, who had drawn quiet, his eyes glazed over and far way. The silence hung on the air until Regulus shivered and pulled his jacket closer around his slight frame.

“She was a Mudblood, seventh year. Her mother and father were there, and her brother. He was ten. I had been so eager to prove myself… Bellatrix just laughed her head off as she tortured them. I… I had to cast the killing curse. I know that sounds like trying to justify myself. But Sirius… the screams... you can't know what is was like... I just had to make it stop. It seemed a mercy to give them peace. After that, it got easier. I gave myself so many justifications. I was building a better future. They were less than animals. If I messed up, I’d face the same torment…

“Stupid, I know. I was still in school. I could have gone for help, Slughorn as the head of my house would have offered aid and was someone I could have trusted. With the school owls, I might have written to you without alerting my allies. Hindsight truly is a wonderous thing. But to my remorse, I was so in love with the perfect future that had been painted in my mind that I did not conceive of these options. I wanted that future and I reasoned with myself surely, the cost would be worth it. In the end.

“One year after I had joined, the Dark Lord requested the use of a House Elf. It seemed a simple enough request that might get me recognised, increase my worth and influence. So I offered Kreacher. I… I told Kreacher to… to do what… to do whatever the Dark Lord requested and then come home… Merlin! If I hadn’t said come home… He would have died. Sirius, you have no idea how heavily that weighed upon me – still does. I told him to come home… The inferi would have drowned Kreacher in that lake. He was so weak from the potion that he had been forced to drink… It was torment to witness. But he made it out and back to me. Back home… When he was well enough, I asked what had happened. And from his story, and my work, I pieced together the pieces. The Dark Lord had made a Horcrux, Sirius. That’s… evil magic, and I do not use that word lightly. Evil enough to make me uncomfortable. 

“So, I hatched a plan. I would go, I would steal the Horcrux. And I would die.”

Regulus paused, finally meeting Sirius’ gaze again, wanting to see some sign of brotherly love and concern. It was Sirius’ turn to wear a blank expression. Regulus briefly closed his eyes, he supposed he deserved that. Staring at his hands, Regulus continued.

“But… I couldn’t… If I died, the secret would die with me. Instead of rushing to my demise, I could instead take my time. Build a plan to ensure my survival and the destruction of the Horcrux once I had obtained it. To that end, I began to seek out a way to hide my plans. Somewhere the Dark Lord would not seek to look nor stumble upon. I found here and I made it as best I could. Then, when you were brought in, I knew I must save you.”

At this, he raised his head, awaiting Sirius’ judgement on the story. His brother’s eyes were stormy and unclear, a frown tugging at his features.

“And how many houses have you attacked? How many people have you killed, Regulus? Tortured?”

Regulus looked down at his plate.

“I never thought I’d lose count.” He whispered. “But it got harder. I never wanted to kill… How many I murdered; I cannot say. Tortured…. Five. I got away with only five.”

“Merlin, only five? And it took you how long to realise this long that you are with the bad guys.”

“Bad is subjective.”

“Yeah, well the Ministry doesn’t kill or torture!”

“I hear its being legalised.”

“Reg, that’s because you guys started this! Besides, most of us disagree with legalising Unforgivable Curses anyway!”

Sirius was staring at him as if he had grown a second head.

“I’m just saying things aren’t always so clear cut, Sirius. Surely you must realise that?”

“Seems pretty clear cut to me.” Sirius said, eyes firm.

Regulus pushed loose strands of hair back, trying to figure out what to say to ease the situation. This was why had put off talking to Sirius. How could Sirius understand the difficulties that Regulus had wrestled with? The turmoil and expectations. Sirius had always known his own mind and refused to allow anyone to tell him it was anything less than perfect.

“I’m not saying I agree with everything the Dark Lord has done or said. There is fairly convincing evidence that killing is a wholly evil act – it is the act that splits the soul and allows the creation of the Horcrux. And the act of torture I deem to be worse, although I have yet to get empirical evidence to back this belief.”

“Reg, listen to yourself!” Sirius exclaimed. “Weighing up the merit of whether or not Unforgivable curses are wrong. They’re dark magic, it’s obvious!”

“Good and evil are not the same as light and dark, Sirius. Dark magic can be used for good. Many consider blood magic to be dark, yet because of it here you stand. It’s dark because of the sacrifices it demands and society’s fear of the power it holds. Likewise, light magic might be used for evil.”

“I notice you gave no example for that.”

“Fine, I levitate some poor, unexpecting muggle into the air and drop them off the edge of a building. I’ve seen Death Eaters do that for sport.”

Regulus was rewarded with Sirius’ flinch at those words.

“Wingardium Leviosa is more a neutral spell.” Sirius muttered, he was chasing a potato around the plate, rolling it through the truffle cream sauce, hitting the remainder of his steak and pushing it away. It had not escaped Regulus’ attention that a single morsel of food had passed Sirius’ lips since Regulus had started his story.

“Fine, what’s a light spell you want me to figure out an evil use for?”

“I don’t want to think about it.”

Regulus rolled his eyes at Sirius.

“I won’t press my point. I know we shall not agree on this matter. You should eat. I know you are hungry.”

“That’s a little hard, knowing my little brother is a killer. That this food, was made by a murderer.”

“It didn’t bother you before.”

“Ignorance is bliss.”

“You were starved. Please, eat, Sirius. If you can’t stomach what I’ve made, the kitchen is well stocked.”

“You don’t get it, Reggie!” Sirius exclaimed, looking into his eyes and searching his face. “You’ve killed and tortured. And I can’t see any remorse in you. How can I stomach food when I’m sitting across from that? I…Could I have done anything to stop you becoming this?”

Regulus swirled the wine in his glass, looking into what blood-red liquid remained.

“Remorse is a luxury I cannot allow myself to feel. Not until my task is done. And as for whether you might have been able to stop me becoming what I am… Is that worth contemplating? We can’t change the past. Believe me, I’ve looked into it. If I could take back the harm I’ve done, I would do it in a heartbeat. The closest I’ve found to altering history is the use of time turners. But getting hold of one is a nightmare and even then, the prevailing theory is that those who use them were already preordained to, i.e. they are not changing history but ensuring it happened. No, Sirius, the past is set and we can only hope to learn from our mistakes.”

“But you are still with Voldemort!”

“Yes. Because to openly declare rebellion would be folly. This mark, it connects me to him. At the Dark Lord’s whim, I can be summoned like some loyal mutt. I will not be free until he dies and so I must ensure that I make him mortal once more, or else perish in the attempt. The former is preferable, as I would like the satisfaction of knowing that it was I that brought down the Dark Lord. To see his face when he realises what his boastfulness and hate has wrought.”

“You’re staying alive and working with Voldemort, out of the pure will to spite him?” Sirius leaned back in his chair, assessing his brother and his sanity levels.

“Simply put.” Regulus said with a shrug. He finished the last morsel and carefully placed the cutlery on his plate with a soft chink. Sirius pushed his potato one more time and then cut off a sliver of steak and chewed it. The beauty of the food was gone, but he could not deny he was starved. And it was literally served to him on a silver platter.

“I don’t like what you’ve done, Regulus. I don’t know if I can ever forgive you. But defeating Voldemort matters. So, if you are on our side, I’ll take it. I’ll get back to the Order, let them and Dumbledore know. He’ll figure out what our next steps should be.”

“Ah.” Regulus said, looking at his brother over the rim of his wine glass, which he was slowly lowering from his lips. It was not a good ‘ah’, Sirius noted with a sinking heart.

“What?” He dared to ask.

“I don’t think you quite understand.” Regulus said, looking at him across the table. “You see, the Dark Lord and his Death Eaters believe you to be dead and I cannot risk them knowing of my defection. As you are foolishly brave, I doubt that if you were free, you could exercise the caution and restraint required to keep up the charade and remain in hiding until I have dealt the necessary blows. So, brother dear, I am afraid that I must keep you here until that day has come.”

**Notes for the Chapter:**

> So, Sirius has found out that Regulus' home is to be his prison and what Regulus has been up to during their estranged period. It's not easy for the two brothers but hopefully they can begin to mend bonds soon. Hope you've enjoyed!


	5. Insomnia

**Summary for the Chapter:**

> Sirius and Regulus both go their separate ways for the night and have their own troubles with sleep.

From once prison to another, Sirius thought sullenly as he lay in Regulus’ spare bedroom (because he refused to think of it as his), dressed in his brother’s choice of nightwear (it was positively Victorian).

After Regulus had gone to bed, Sirius had tested the front door. The first hurdle had been the locked door, which Sirius had picked it with ease. However, it seemed that even if Regulus was scarcely using magic, clearly he had thought it pertinent enough to cast wards to keep Sirius from leaving. When he tried to step towards freedom, an invisible force kept him from exiting. He had even tried as Padfoot, but it seemed he registered just the same to the magic. The windows, Sirius had hoped, would not be warded against his escape.

Alas, they proved to be impassable.

It turned out he had been right about it being an industrial building. They were on the top floor, with the ground a sickening distance below. While he was adept at wandless magic, he did not fancy his chances with that leap. He’d probably end up as a paste of jam over the pavement, an entirely unwanted outcome. He could maybe use the curtains and sheets to make a rope to clamber down. If he could make it to a lower apartment, smash in the window, explain the situation to the occupants.

And then what? It would undoubtedly end up involving the muggle police if he said that the creepy dude in the penthouse apartment had kidnapped him and held him prisoner and he couldn’t quiet think of a lie that would give Regulus any alibi. Then there was also the very probable fact that Regulus would not allow himself to be taken and imprisoned by Muggles. Obliviate would be all that sufficed to escape muggle clutches but with all that had been brought to light about his brother, Sirius was afraid that Regulus might use something worse. That was a risk that he could not have on his consciousness.

He sighed, turning in the bed. Regulus did seem to not agree with the killing. He had said that the act ripped the soul and was thus measurably evil. Maybe he wouldn’t kill a Muggle police person. Sirius’ mind was not content with this though and started to list all the horrendous hexes that he might expect a Death Eater to use on a Muggle.

Merlin! Sirius needed to talk to someone. James. Remus. Peter. Lily. Just someone. But the chances of getting communication out of this prison was very unlikely. They would know he was missing, of course. They should have figured that out days ago when he had been captured while on one of his missions for the Order. Well, Remus may not know yet. He had his own secret missions, Merlin knew where. He might not be back yet. But James would know. And he would check the mirror and see that Sirius was not answering. He would be looking.

Even if the Death Eaters had put it out that Sirius Black was dead, there would be no body to prove it. James would keep looking. That’s what he told himself. He could rely on James.

The only active option left to him was to try and aid Regulus. As his brother had said, once Voldemort was made mortal and had been defeated, Regulus would be free from the stupid dark mark that he had had carved into his own skin. Sirius was still trying to come to terms with the fact that his little brother had willingly done that to himself. How could he have been such an idiot? Huffing, Sirius turned over in bed, trying to figure out how could he help while stuck inside and without a wand.

As time ticked by and no answers came, Sirius stretched out his hand, moving his fingers carefully. The healing process was slow and he could feel the bone deep ache of mending. The broken leg still twitched. Sirius was well aware that his body was still trying to figure out how he could have been tortured scarce hours ago yet now he was here, in the lap of luxury. Every now and again, his heart would skip a beat or start racing. Without the curtains pulled around his bed, shadows became figures. With them closed, he could hear floorboards creaking as enemies closed around him, ready with crucio on their lips.

He refused to look at the time. He would not find out how many hours sleep had avoided him.

Maybe he needed some more potions. There had been plenty of doses of pain-relieving potions. Enough time had surely passed since his last dose and he didn’t really care if not. They were more guidelines. Probably. Maybe… Eh, Sirius thought. Drowsiness was a side effect and that would be most welcome.

Getting up, Sirius hissed as his leg protested, shaking with a weakness that he was loath to admit. Dark curses always took longer to heal otherwise this could have been fixed in a flash. Instead it might take a couple of days for whatever magic his brother had used to heal it. Regulus had said he had done some healing magic. If he hadn’t, Sirius expected he was extremely numb to pain at this moment in time, which would not be a good sign. Yeah, Reg was probably being truthful.

Limping into the living room, Sirius grabbed some of the vials, took a quick look and then downed them. Slowly, he made his way over to the television, fingers following along the wire until he reached the plug and found a socket to put it in. The hum of electricity was a familiar friend and put him at ease. Sirius cast his gaze around for the remotes. Neatly placed on the mantle. But without batteries. Because of course his brother wouldn’t know. Sirius sighed and felt along the edge of the television for the buttons.

Eventually, he found some light hearted comedy that was on an infinite rerun. He didn’t know what it was, nor cared much for whatever plot it had. It was white noise and something to stop his head running in endless circles. Making his way back to the sofa, Sirius settled down and finally closed his eyes.

-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-

“They’re coming!” The voice echoed out loud and clear, magically amplified above the din of the screaming and burning. Regulus glanced up, looking for the crier but a flash of red light and a body went flying, hitting the ground with a heavy thud. Glowing in white light, the Order of the Phoenix had arrived. Regulus scanned its ranks, hoping against all hopes that he wouldn’t see Sirius in their number.

A silvery dog lunged at a dementor, forcing it back from the muggle it had in its clutches.

“Finally, a challenge!” Bellatrix grinned from besides him, her hair like a nest of snakes shimmering in the flickering firelight.

“Blood traitors do make better sport.” Regulus agreed, although how much his heart was in it, he could not say.

Spells had fired back and forth. The air was dancing with colours and screams. Regulus watched as one Order member’s patronus failed, flickering out of existence as dementors swooped in. Then a stag was chasing them back, antlers bright and highlighting the ghostly visage of the dark creature.

“Nice one, James!” Sirius laughed from where he was duelling with Bellatrix, his giant hound patrolling around the Order and snarling its spectral teeth at any who wished to come close. Regulus broke his focus from the scene and deflected a hex sent his way, firing his own curse in return. The battle raged and time past. Suddenly, he was alone and he felt skeletal hands upon his neck. The darkness of a Dementor loomed, swallowing his vision.

Once he had stood at a beach and watched as the tide rushed in, spilling around his feet, breaking against his legs. Then the sea had pulled the water back to itself. The sand and water sucked at his feet, tugging him towards its greyness. This was a lot like that. But deeper. Darker.

Searching.

Then he was tumbling down. Head smashing against the ground with a crack.

“Not even a soul to remove.” A voice said, swimming into his vision. Potter.

“Best put him out of his misery then.” Sirius…

A wand was pointed at his face. A flash of light.

Regulus woke up with a start, feeling beads of sweat dripping down his neck, his body trembling like dead leaves on a tree buffeted but autumnal storms. He stared at his pale arms, desperately trying to force them to be still and obey his will. With some level of shock, he realised that there was water on his face. He was crying. Regulus elected to pull his sheets closer to his body and wait for this fit to cease.

It was not his first nightmare. His body just needed time to adjust and remember that it wasn’t real.

It wasn’t real.

At least… not all of it.

The attack had been. He remembered that. They had managed to gather a few dementors to their side and the Dark Lord had suggested that they try them out on a Muggle population. Fresh meat for creatures long forced to withhold themselves from their natural prey. He remembered being forced to retreat by the Order. And disappearing down an alley. Part of their tactic was to scatter into the darkness. It split the Order up to follow them (alone, they were easier targets) but also gave the Death Eaters a chance to escape. Their numbers were not large enough to sustain too many casualties.

He had run down the dark lane and stumbled upon a dementor, hood slightly lowered as it pressed its mouth against some unsuspecting muggle. The muggle was cowering. Crying. Begging. A strange light began to appear and Regulus realised he was seeing the consumption of a soul. That this was sure proof that muggles did have souls. Were human. For some reason, he had not considered that when they had taken the dementors to wreak havoc on the muggles. Or chosen not to realise the implications. It was easier to think of muggles as animals rather than beings like him.

The creature – the human – whimpered, cowering in fright and trying to pull away from the dementor that it could not see. The sound shook Regulus from his revelation and he had fired the killing curse, to ending its miserable, non-magical life.

In the same moment that the curse had left his lips, a silver dog shot past and latched onto the dementor, driving it back. The body hit the ground with a sickening thump. Regulus had turned and saw Sirius, wreathed in anger and the glow of battle. To his shame, Regulus had apparated.

He had spent the next day wondering about the worth of Muggles and how alike they might be to witches and wizards. After he had discovered the Dark Lord’s secrets, he had pondered on the state of his own soul and whether his own killings had likewise shattered his into splintered shards. The conclusions were not good.

Regulus sighed, drawing back the curtains around his bed. Even if he claimed victory over the Dark Lord, for his crimes, he would surely be sentenced to Azkaban. Depending on how instrumental he was in the destruction of the Dark Lord, it would impact his sentence. The Black name carried weight and their coffers were flowing. He had hoped that that might avoid a life sentence but with Barty’s father… it seemed unlikely. He had heard about the senior Crouch from the younger and it did not bode well. At least they would not give him the dementor’s kiss. He had not done enough to warrant that.

Slipping out of the cold warmth of the bed, he pushed aside the curtain to peer through the window. Light had begun to tint the black sky. It was nearly early morning. He could hear the sound of voices from the Living Room and with a frown, Regulus moved towards the door. His wand was hidden in the wall, illusions and runes keeping it hidden and accessible only by his own magic. Only with his signature and code, could the wand be accessed. A useful precaution now Sirius was being held here against his will.

Lifting the wand, he cautiously approached the living room.

An unnatural light lit it, coming from the box that Sirius had called a telly. Small figures, like a photograph moved and spoke to each other but did not notice his approach. As he came closer, he heard gentle snoring coming from the sofa. Sirius was sprawled out, arm hanging over the edge.

Regulus let out a breath. They were safe.

Out of precaution, he checked the rest of the apartment, just to be certain. There had been no breaches. Returning to the living room, he glanced at the box, which still had its occupants oblivious to his presence. He did not understand muggle technology. He walked over to a cupboard and pulled out his spare blanket (the clean one) and draped it over his brother’s sleeping form. Sirius shifted but did not wake.

Silently, Regulus padded back to his room, deposited his wand in its hiding place, traced the runes and then went to manually light his candles. He would not sleep before daybreak so he might as well put these extra waking hours to use. A hidden compartment in his chest of draws held his work and decoy locket that he had had created. Plans on a potion that might negate the Dark Lord’s own. Ways to destroy a Horcrux. And his research into whether or not someone could create more than one.

Regulus was not going to allow himself to make some stupid mistake in assuming the Dark Lord did not have further backups. He would not underestimate the man again.

**Notes for the Chapter:**

> Bit of a slow chapter but they both have their difficulties that they need to think through. Next chapter should definitely have some proper brotherly bonding. Hope you've enjoyed!


	6. Boredom

**Summary for the Chapter:**

> After some time as his brother's 'prisoner', Sirius starts to get very bored. The brothers snipe at each other and then settle in for some family bonding and getting some things off their chests.

Sirius was growing bored, Regulus could tell. He wondered if his brother had ever spent this much time cooped up inside. Sirius was pacing, casting glances out the window, at the door, occasionally casting glares at Regulus.

“You should settle down with a book. You can’t keep pacing.” Regulus advised, not for the first time. The first time he had told Sirius this had been when Regulus had returned from informing their mother that Sirius was ‘dead’. Not a pleasant ordeal – Regulus hated lying to his mother – but it was a necessary evil. The news of Sirius’ murder had come out to the wider wizarding world not too long after. Regulus had considered buying a paper so his brother could get it into his head that this was the situation. But he figured it would just make Sirius more hostile.

“I should be out there. Not stuck in this gothic horror show.” Sirius said, going over to the window and staring out.

“And how many times must I remind you that your freedom would destroy all that I have worked towards. You cannot hope to defeat the Dark Lord through brute strength and force.”

“Dumbledore-”

“Allows the Dark Lord to mark his followers while still at Hogwarts. He has let many of his students join the war while at school if he does not care for them, myself included. Or if he does care for them, they sign up upon graduation, like you and your friends. I see no reason for you to put your faith in that man.”

“He’s the only one that Voldemort fears.”

“And that is no reason to trust him.” Regulus countered. He was never going to finish his book on the muggle view of the universe at this rate. Such a shame, it seemed such a curious alternative to what wizards knew.

“Fine. What about Moody?”

“He’d send me to Azkaban before I even had a chance to utter a breath. And that is a place that I do not intend to visit. Not if I can help it.”

Sirius grumbled and was back to pacing.

“I hate waiting. Why are you even here? Shouldn’t you be off with your Death Eater buddies?”

Regulus let out a long sigh.

“You’re insufferable.” He muttered, but he had promised himself he would be lenient with Sirius. His brother had been tortured and killed. Now he was imprisoned. It likely did not give him the best of health or attitude.

“We should be doing something. You said he had created a Horcrux, you know where it is. Why aren’t we getting it and destroying it?”

“Because I do not know if the Dark Lord will be alerted to its theft or if we have to be concerned that he may have created more.”

“Live a little, Reg. What’s life without a bit of danger?”

“Sirius, this is my life that is at risk. I do not desire to treat it carelessly. I am not you.”

“That much is obvious. Afraid of having to break ties with your murderer friends?”

Regulus rubbed his brow. Sirius had become snarkier during his time as an unwilling guest in Regulus’ abode.

“This mission is too important to make a mistake. What if I fail? Who else is left to stop the Dark Lord?”

“Merlin, us, Reg! The Order! The Aurors. This doesn’t rest all on your shoulders. You aren’t the only one responsible for cleaning up this shit show.”

“And how well have they been doing, Sirius? How close are your guys to winning the war? Tell me, have they figured out that the Dark Lord is now functionally immortal?”

“Don’t get snarky, Reg. It doesn’t suit you.”

Regulus clenched his fists. Sometimes he wondered if Sirius was trying to irk him into throwing his brother out onto the streets. He leaned back into his armchair, glancing down at the Dark Mark on his arm. Sometimes, he could go weeks without a summon. The waiting was a special kind of torment. Not because he wanted to serve but for fear of what he would be asked to do. Sometimes, he wondered how much more he could take before his façade broke. He was a Slytherin. He was a Black. Cunning and ambition ran through his veins. But there was only so long a mind could cope with the horrors he had committed.

He glanced up and saw Sirius likewise staring at the Dark Mark and Regulus flipped his arm over to hide it.

“You were an idiot. Getting in that deep. You should have realised what you were getting into.” Sirius said, arms crossed and staring at him with stormy eyes. Regulus stood up and stalked to stand before his brother.

“You have no idea what it was like, Sirius. You don’t even have an inkling of what decisions I had to make.”

“Oh, let’s see. Join a murder cult and torture innocents or you know, not. Such a hard decision. I wonder what I should do?”

“It’s was never as simple as that. You just can’t see it because you expect everything to be black and white! But it isn’t. We aren’t in your naïve little dream world.”

“I’m not the one fooling myself into believing that black is good. You’re just too enamoured with blood purity and dark magic to realise how far you’ve fallen. Merlin, that house twists all who live in it and you let it get to you. I thought you were stronger than that. That you were too kind and soft to join Voldemort. But you let that place turn you into this. A little murderer that mother could be proud of.”

“No!” Regulus said, backing away from Sirius, a finger pointing accusatively at his brother.

“You don’t get to say that. You left me. You did this to me! You left!” He shouted that last bit, the world beginning to sway around him. His eyes were a starless night, sunken deep into a bone white face as he stared at Sirius.

“I waited! I waited to see. Because if you loved me, you’d have come back. You would have tried to break down the walls I had to erect to keep myself safe. You would have fought for me! We were both at Hogwarts when I joined the Dark Lord and you never even noticed the path I was blindly forced down. Never tried to speak to me, to stop me. You were too busy running around with your group of blood traitors, worshipping the ground Dumbledore walked on and your own self-image. Well, where were they? Did they save you from the Dark Lord? No, it was me. Little Regulus, who’s not worth the time of the great Sirius Black.” He spat the words at his beloved brother, wielding internalised pain like a dagger.

Regulus tore open the drinks cabinet and poured himself a shot of whisky. Because if he drank it in a glass, he wasn’t mother. He didn’t have a problem. It burnt his throat. He poured another shot and downed it. The alcohol stung his eyes but at least it wasn’t tears. He did not feel anything. He was above hurt and pain. The glass felt smooth and cold beneath his murderous fingers. A universal balm.

“I promised myself I wouldn’t talk about it.” He muttered. “You were dead. You were tortured. This isn’t about me.” He poured a third shot. And filled a second glass which he handed to Sirius.

“To your good health.” He said, raising his glass with an amused smirk. Because what health did the Black family have but alcoholism and insanity?

Sirius was staring at him, holding the glass in his hand looking rather like a deer frozen in shock before a dragon. Regulus shrugged and sipped the whisky, wondering how many glasses he would get through before the day had ended. He had not meant to shout. He had not meant to talk to Sirius about his past. He was halfway through the glass when Sirius suddenly joined him.

“You know, it’s a little early to start drinking.” Sirius said, having downed his own glass. The quip fell cold as Regulus topped up their glasses and put the whisky bottle on the table.

“Yeah. Something like that.” He muttered, watching as Sirius downed his second glass, pouring himself some more without asking.

“So, are we going to finish the bottle before we talk about that outburst?” Sirius queried, raising a delicate eyebrow.

“I’ve got several other bottles I think we should get through before we try to broach our messed-up history.”

“No need to be polite, Reg. Fucked up is a much better descriptive term for what we’ve got going.”

“I have never understood your obsession with foul language.”

“Yeah, well I’ve never understood your obsession with dark magic.”

There was silence for a heartbeat before both brothers broke out in a laughter only achievable with the aid of alcohol. They ceased, only to drink a further shot of whisky. Regulus topped them up and wondered at how alcohol could broach the chasm that stretched between the two.

“Did you… really want me to try and get through to you? I… I thought you didn’t want anything to do with blood traitors. That you couldn’t leave home because you wouldn’t live like the great unwashed.”

Regulus sighed, swallowing two shots of whisky to aid in his answering.

“At the time, I wanted to see you try. Even then I don’t know if anything you said could have changed my mind … but I thought if you had ever cared for me, you would have fought against my attempts to push you away. And as I fell under the sway of the Dark Lord and saw him for what he was, that want changed to hate. I couldn’t stop thinking about how different things would have been if you had forced me out of there. You had the sense to escape while you could but made the decision to abandon me. Because that’s what not fighting me became.”

He sighed and poured himself and Sirius more whisky.

“I looked into ways to change that. I checked everything in wizarding law about time travel. And when I assembled my library here, I discovered Muggles had their own theories on time travel. None of it is promising for fixing what happened.”

“Yeah, I’ve been meaning to ask about the library. Did you just buy one of every book in a bookstore?”

“Was it that obvious?”

“Kind of. It’s very eclectic.” Sirius grinned, an amused look on his high features. Regulus could feel the pleasant numbness and detachment from the world that alcohol brought. It was a strange sense of relief that he welcomed like an old friend.

“So, being tipsy is probably not best for this conversation but I doubt its going to happen any other way-” Sirius began.

“I thought blind drunk might be preferable.”

“Ah, but then would you remember it?”

“I was hoping not to. What with feelings kind of being frowned upon in our family.”

“Tough. I’m making a Blood Traitor out of you. We’ll defeat Voldemort, watch television and talk about our feelings. Right. I’m sorry, Reg. For not fighting. I didn’t think beyond what was the customary bare minimum afforded between brothers.” Sirius took another shot and Regulus wordlessly topped their glasses.

“I knew that place was wrong. And while I may not have been old enough to know how to handle it, I damn well should have known enough to talk to Slughorn. Or Minnie. An adult who was entrusted to look after our health because I knew that that house was not safe. I knew a war was starting and I should have been smart enough to know that you’d be in the front lines for drafting. I’m sorry, Reggie. Merlin! I’m sorry that I allowed all of this to fucking happen.”

“It’s not your fault, Sirius.” Regulus said softly. He knew Sirius wasn’t to blame. But he knew a dark part of his heart would always yearn for Sirius to have fought for him. Because Black children did not know love without pain.

They took another shot together.

“I suppose I should say, I’m sorry for killing you.” Regulus said, causing Sirius to laugh and spill the whisky he was pouring for them.

“I get the feeling that I would be much deader if you hadn’t.” He said, downing the haphazardly filled glass.

Regulus brought out a second bottle.

“I wanted to talk to you. About the Horcruxes. I wanted to write and to mend things. I was nearly ready. I didn’t want it to come down to this.” His own words were beginning to slur, Regulus noted as he opened the second bottle.

“I know.” Sirius said softly. “That room, you couldn’t have got it ready for me so quickly.”

“I was afraid you wouldn’t listen. Wouldn’t accept me. Would hate me for what I’ve become.”

Merlin, his voice sounded so small. Curse alcohol for forcing him to voice his emotions. They should have waited for blind drunkenness. Regulus had another glass. Blacking out couldn’t come soon enough.

“You’re my brother, Reg. I might hate you, but I can’t hold that hate forever. I hope I would have listened.”

The rest of the afternoon turned into amicable drinking and a rather poor attempt at introducing Regulus to Chinese food. It turned out ordering food while drunk was not the easiest of tasks, much less eating it neatly. But at least they could imagine what it felt like brothers.

**Notes for the Chapter:**

> Hope you've all enjoyed the Black Brothers bonding! They really need to spend more time as brothers and talking about their feelings. Probably without alcohol, but baby steps. More dramatic plot should be starting soon as Regulus begins to take action.


	7. Cracks

**Summary for the Chapter:**

> Regulus has been called away on a mission for the Death Eaters and Sirius worries.

Sirius paced the Living Room. It was surprising he hadn’t worn a trail into the flooring. The door rattled and he glanced up, steel eyes staring at the traitorous hunk of wood that kept tempting him with Regulus’ return. But it was just the wind, teasing him with false hope. He snarled at it, a sound more likely to come out of Padfoot’s mouth and it spoke of Sirius’ concern.

Five days ago, Regulus had left.

They had just been starting to mend their messed-up relationship and Sirius was going to try and convince Regulus to get batteries so they could watch the television. Or rather, so Sirius wouldn’t have to get up to change the channels when he watched it. He had hoped, that when Regulus saw how easy watching TV was, he might consider settling down in front of the screen. But before Sirius could speak, Regulus had frozen. Somehow, his white skin paled and it did not escape Sirius’ notice as Regulus’ hand wrapped around his left arm, that the Dark Mark had grown blacker.

“I have to go.” Regulus said shortly, rising and heading into his room. Sirius had stared after him. Had suggested softly that Regulus ignore the summons. That he start openly rebelling. But his brother just gave him an empty look and closed his bedroom door. A few minutes later, he emerged, every ounce the pure blood he was. The black cloak was lined with velvet green, silver buttons proudly displayed the snake of Slytherin. A silver mask sat on his brother’s face, skeletal and all too familiar to Sirius. He stared at the wand in Regulus’ hand and made a bid to grab it, only to find himself magically pushed back.

“I know not how long the Dark Lord will require my services. The kitchen is well stocked. Should I be captured by your side do not fear, I will pass on your location. They will liberate you. Should I die, these wards will fall, and you will be free to walk out on your own.”

His brother’s words had the air of aristocracy dripping from each syllable and it fell so naturally from his tongue that Sirius felt doubt flood him. Regulus was his brother, but could he tell which Reg?

In that first hour, he had gone to the spare room. His room. He had stared at the red curtains. The red lampshade. He had traced the delicate gold patterns. Tried to remind himself that this spoke of Regulus’ betrayal of Voldemort long before their reunion.

While not suitably calmed by this reminder, it had done its trick and Sirius had gone to the kitchen to make himself a sandwich. Enough time had passed that he had felt hunger, ignored it and felt it return again. When the sky grew dark and his brother did not return, Sirius opted to search through Regulus’ drink cabinet.

The next morning found him still alone. Sirius had tried to leave through the door but the wards still kept him in. He tried to comfort himself in the knowledge that Reg was still alive.

Sirius searched through the apartment. The only thing he found of use was a secret draw in Regulus’ room that held all that Regulus had discovered about Horcruxes. While useful, that did not offer Sirius any imminent help with escaping. Mentally, he filed away the location and the information on the potion and inferi infected lake.

The next day, he had howled until his throat was sore, wondering if the neighbours might come and find out what was the source of some dog’s distress. Not a creak. Regulus must had silenced the apartment. Escaping through the window with sheets and curtains tied together was starting to look very appealing.

He slept on this thought. Nightmares plaguing him of Regulus’ body turning up dead somewhere. Of Regulus clawing his way back to their home and finding it empty, Sirius long fled, and no one to tend to his wounds. Of slow and agonising torture. Sirius had awoken and finished off Reg’s drink cabinet. Then immediately regretted it when he realised that meant there was no more alcohol to act as a balm to him. Sirius did not think he had spent this long alone and was not looking forward to the idea of doing it sober. It was agitating. It was maddening. 

He started to tie sheets together. Because he had to do something. Even if he feared that he might be abandoning Regulus. Because at least he could search for him if he was free. He wouldn’t have to wait here for whatever made its way back to him.

The door opened.

Sirius glanced up, sharply, ready to shift at a moment’s notice. He may not have a wand but Padfoot was a force to be reckoned with. The figure at the door had a face worn beyond all belief. Dark circles rimmed feral, pitch black eyes, which seemed too tormented to dart around. They just stared ahead. Black hair fell wild and unkempt from the ice-like face. Because his skin was as if ice, pale and transparent. The black robes of a Death Eater seemed, if anything, more sinister in stark contrast to the paleness of the young man’s flesh. Here, was a picture of madness and nightmare, framed by the doorway.

“Reg-” Sirius began, but his brother strode past him and to the kitchen before the door even had a chance to swing to. The silver Death Eater mask clattered, abandoned to the floor below, the echoing sound of its fall to be replaced by a dreadful retching. Out of fear and brotherly loyalty, Sirius followed the haunted man. Coming into the kitchen, his grey eyes made out the dark form, hunched over the sink and trembling, wand grasped tightly in his hand. He could make out the bones and tendons in that hand, almost as if it were a skeleton that held it. Cautiously, Sirius approached, carefully placing a hand on Regulus’ back. His brother flinched, cast a wild and fearful glance his way and then turned back to the sink. As Sirius rubbed his brother’s back, he noticed the black bile and blood that escaped Reg’s mouth.

Wordlessly, Sirius put his spare hand over Regulus’ trembling one, gently loosening the death grip on the wand.

As the wand passed into his grasp, Sirius knew his chances of getting aid from it were slim. He knew not what core or wood Reg had but it rejected Sirius as different and other. It might as well have been dead wood. Still, it was safer to have it out of Regulus’ shaking hands which now clutched at the sink as if it were the only thing keeping him upright. Not ceasing from rubbing his brother’s back, Sirius placed the wand down on the kitchen counter and went to hold Regulus’ hand. There was a pause as fingers searched for strength and then the hand latched onto his as if it could not exist without him.

Sirius did not let go as retches slowly turned into sobs and tears diluted black bile.

When the sobbing had faded into silent tears with gasped breaths which slowed into the gentle rise and fall of an exhausted man, Sirius raised his brother’s head to look into broken eyes. With brotherly love, Sirius wiped the last of the bile from Regulus’ mouth and wordlessly, he led him to the living room. Reg followed without a protest and Sirius carefully settled the younger man on the sofa. He brought out a blanket and wrapped Regulus in it. His brother scarce seemed to notice. Sirius tugged the blanket tighter around his brother and placed it in Regulus hands. They seemed to remember their own as after brief hesitation, they clutched at what had been placed in them.

Regulus’ gaze had not shifted through the entire interaction.

Returning to the kitchen, Sirius stared at the bile and blood in the sink before washing away the dark stain. If only it could be so easy to remove the images from his head. He poured a glass of water and brought it through to the living room and the frozen figure. With gentle hands, Sirius helped Regulus to sip at liquid until hesitant mouthfuls became desperate gulps as his body took over, realising what was being offered. This way they got through three glasses before his brother managed a small shake of his head. Sirius left the glass on the coffee table.

“Reg…” He tried again but there was no sign of recognition in his brother’s eyes. They may have twitched towards him, but Sirius could not tell if it was because he had uttered a sound. With a sigh he smoothed his brother’s hair out of his face. The skin was cold and he could feel slight shivers beneath his hands. Sirius walked over to the television and flickered through until he found some harmless program. Regulus might watch, he thought.

With an act of trust, he shifted, revealing his animagus form and padded over to his little brother, carefully clambering onto the sofa and arranging himself so his body heat would warm the man. Raising a giant head, he nuzzled his brother’s frozen face and then lowered it to rest on Reg’s lap.

Several shows passed until he felt a clammy hand gently fall onto his head. A few hours later and fingers tentatively scratched through thick fur, getting into those sweet spots on his dog’s head. Sirius gave a low rumble of approval, looking up at his brother, eyes still haunted and staring. With a humph, Sirius focused his attention back on the television. It was interesting to watch it with his dog eyes, if sleep inducing. A dog’s brain was not always the best.

He woke sometime later, functionally a blanket for Regulus who’s soft breathing informed him that the man was finally asleep, nestled closely into the mass of dark fur. Sirius carefully placed his nose to his brother’s cheek. He felt warmer, more alive than he had been before. Regulus did not stir and Sirius let out a sigh of relief. He closed his eyes and went back to sleep.

The next time he awoke, he felt a hand stroking his dark fur and he looked up at Regulus who looked almost human once more. Sirius gave a tail wag and was rewarded with a ghost of a smile.

“I didn’t know you had become an animagus.” Regulus’ voice was hoarse and croaked as he spoke. But he was talking. Sirius felt relief return to him. Lifting his head, he gave his brother a quick doggie grin before shifting back to himself.

“Reg,” He tried but his brother would not meet his eyes. Sirius placed a hand on his brother’s hand and stared ahead.

“I… I can’t continue. I can’t keep doing this…” Regulus said, voice cracking under the weight. Sirius rubbed his brother’s hand with a thumb. A reminder that he was here. Regulus lapsed into silence.

“Can you talk about it?” Sirius asked softly.

He felt rather than saw as his brother shook his head, a muffled sob in his chest. Regulus was too young for this, Sirius thought with sorrow.

“It’s OK. You don’t have to.” He promised. Sirius waited, as his brother raked skeletal hands through matted dark hair.

“I keep waiting. Merlin, I keep waiting for the family insanity to take me. So I can at least have a semblance of peace. Of normality. Because it makes no sense… no fucking sense that I should have this much clarity of thought… after everything... The world is just some sick, shattered joke, mocking me. How can I still be sane when everything else isn’t?”

Regulus’ dark eyes looked desperately into his and Sirius pulled his brother in close for a hug.

“Oh, Reg.” He crooned softly, rubbing his brother’s back. “I’m here. It’s okay. We’ll get through this together. You’re not alone anymore. You don’t have to shoulder this burden by yourself. We’ll fix this.”

“Sirius… If you knew the things I’ve-”

“No. Don’t think like that. Regulus, you are not a bad person. You’re a good person. A very good person. You’ve fought for Kreacher and treating him like he’s a decent human being. You chose to stand up to Voldemort. You became a spy against him because that was the right thing. You saved my life. You are a good person, Reggie. A good person who very bad things have happened to. We're going to sort this. I promise you.”

**Notes for the Chapter:**

> So, drama is starting. Wheels are in motion. And I have deadlines coming and while I've been fairly regular, things might be more sporadic. I hope you have all enjoyed this little chapter and next one, we shall hopefully find out what Regulus has been up to.

**Author's Note:**

> Just a short little prologue before the bulk of this. Not sure how many chapters there will be yet. Hope you all enjoyed!


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